package scenic.study.thinkinjava.io;//: c11:Blips.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// Simple use of Externalizable & a pitfall.

import java.io.Externalizable;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;

class Blip1 implements Externalizable {
    public Blip1() {
        System.out.println("Blip1 Constructor");
    }

    public void writeExternal(ObjectOutput out)
            throws IOException {
        System.out.println("Blip1.writeExternal");
    }

    public void readExternal(ObjectInput in)
            throws IOException, ClassNotFoundException {
        System.out.println("Blip1.readExternal");
    }
}

class Blip2 implements Externalizable {
    public Blip2() {
        System.out.println("Blip2 Constructor");
    }

    public void writeExternal(ObjectOutput out)
            throws IOException {
        System.out.println("Blip2.writeExternal");
    }

    public void readExternal(ObjectInput in)
            throws IOException, ClassNotFoundException {
        System.out.println("Blip2.readExternal");
    }
}

public class Blips {
    // Throw exceptions to console:
    public static void main(String[] args)
            throws IOException, ClassNotFoundException {

        System.setErr(System.out);

        System.out.println("Constructing objects:");
        Blip1 b1 = new Blip1();
        Blip2 b2 = new Blip2();
        ObjectOutputStream o =
                new ObjectOutputStream(
                        new FileOutputStream("Blips.out"));
        System.out.println("Saving objects:");
        o.writeObject(b1);
        o.writeObject(b2);
        o.close();
        // Now get them back:
        ObjectInputStream in =
                new ObjectInputStream(
                        new FileInputStream("Blips.out"));
        System.out.println("Recovering b1:");
        b1 = (Blip1) in.readObject();
        // OOPS! Throws an exception:
         System.out.println("Recovering b2:");
         b2 = (Blip2)in.readObject();
    }
} ///:~